Major function of Vitamin E in the body –
**Core Concept**
Vitamin E is an essential lipid-soluble antioxidant that plays a crucial role in protecting cells from oxidative damage caused by free radicals. It is a chain-breaking antioxidant that neutralizes lipid peroxyl radicals, thereby preventing the formation of lipid hydroperoxides.
**Why the Correct Answer is Right**
The major function of Vitamin E is to act as a free radical scavenger, particularly in the lipid bilayer of cell membranes. It does so by donating a hydrogen atom to the lipid peroxyl radical, thereby stabilizing it and preventing the propagation of lipid peroxidation. This mechanism helps to maintain the integrity of cell membranes and prevent oxidative damage to lipids, proteins, and DNA. Vitamin E also plays a role in the protection of low-density lipoprotein (LDL) cholesterol from oxidation, which is a key step in the development of atherosclerosis.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because Vitamin E is not primarily involved in the regulation of gene expression or as a cofactor for enzymes involved in DNA repair.
**Option B:** Incorrect because while Vitamin E is an antioxidant, its primary function is not to scavenge superoxide anions or other reactive oxygen species.
**Option C:** Incorrect because Vitamin E does not play a significant role in the regulation of blood pressure or as a vasodilator.
**Clinical Pearl / High-Yield Fact**
Vitamin E deficiency can lead to neurological symptoms such as ataxia, dysarthria, and weakness, particularly in individuals with fat malabsorption syndromes like cystic fibrosis or Crohn's disease.
**Correct Answer:** D.